Navigation systems are known using information carriers for storing cartographic data, such as road maps and navigation maps, as an aid in navigating vehicles, such as automobiles, on a trip. While magnetic tapes or discs may be used for storing such data, the invention has particular utility in connection with record discs storing information and capable of being read by laser for producing audio or video representations of the cartographic data stored on such navigation discs. For purposes of the following explanation of the background and the invention, reference will be made to record discs but it should be understood that this term is meant to cover discs or magnetic tapes stored in cassettes or the like.
Such navigation systems conventionally employ satellites, transmitter networks, or the like to fix the exact position of the receiver and combine that information with the cartography of a region from a record disc to enable a user of the system to navigate a vehicle by showing the user the direction and road to take to a desired destination.
The same type of record discs used for storing cartographic information to be reproduced in audio or video form are used for storing music and action entertainment for reproduction in audio or video form. It is now proposed that it would be desirable to provide an system having a magazine for receiving a plurality of record discs of both navigation and entertainment types, for example, reserving one compartment in the magazine for a navigation record disc and the other compartments of the magazine for entertainment record discs. Furthermore, it is proposed to employ a record changer for switching the playing between the record discs. Such a changer may be located in the trunk of a vehicle and operated by remote control by the driver.
In conventional record changer apparatus, a control system provides for successive or selective playing of the record discs according to a program selected by the user. When the operation of a program sequence is interrupted and the playing is subsequently resumed, it would be conventional for the apparatus to resume the playing of the record disc at the place of interruption, a system for storing the positional location of interruption being disclosed in U. S. Pat. No. 4,527,265, provided that the same sequence is followed as specified by the program.
If the sequence of the program is altered, the device disclosed in the aforesaid U.S. patent does not retain the positional information, which is erased, and a changer equipped with such a device simply provides for the playing of the selected disc.
This normal operational mode becomes a major handicap for a changer which provides for the selection of one or several record discs stored in a magazine containing information to be used by a system independent of the changer as, for example, a navigation system.